1. Field of the Invention
The present invention relates to an engine mount, more particularly to an engine mount which is installed between a powertrain such as an engine or transmission of a vehicle and the vehicle structure such as a sub-frame where the powertrain is installed and supported, to thereby inhibit vehicle vibration from being transmitted between the powertrain and the vehicle structure, due to road conditions, engine operation, power transmission and the like.
2. Background of the Related Art
In general, a hydraulic engine mount provides sufficient damping to the rigid body mode control of the engine during the operation of a vehicle and at the same time can isolate vibration from the engine, thereby providing an excellent vibration isolation performance, as compared to a rubber engine mount. Thus, luxurious vehicles employ such hydraulic engine mounts.
FIG. 1 shows a conventional hydraulic engine mount 10. This engine mount 10 includes a mount body having a rubber isolator 11 filled with liquid, a lower cover 12 installed at the lower portion of the rubber isolator 11 and a metallic inserter 13 installed at the top face of the rubber isolator 11.
The metallic inserter 13 is provided with an upper fastener 15 protruded upwardly so as to be inserted into and fixed to a hole formed in the bracket of an engine or transmission or the like. Installed in the bottom face of the lower cover 12 is a lower fastener protruded downwardly so as to be inserted into and fixed to a hole 22 formed in a vehicle frame 20 or the like. A guide pin 17 is installed in a way to protrude downwardly spaced apart from the lower fastener 16, thereby preventing rotation of the engine mount 10 installed in the vehicle frame 20 and the like.
As shown in FIG. 1, the conventional hydraulic engine mount 10 is fixedly mounted on the vehicle frame 20 in such a manner that the lower fastener 16 and the guide pin 17 are inserted into the holes 22 and 24 respectively and then a nut 18 is tightened into the lower fastener 16 from the bottom face of the vehicle frame 20. Here, the lower cover 12 is directly contacted with the vehicle frame 20.
The conventional hydraulic engine mount 10 of FIG. 1 can provide sufficient damping to the rigid body mode control of an engine during operation of a vehicle and also provides an advantage of isolating vibration from the engine. However, this can not avoid structural resonance at a high-frequency range. Thus, in case where the conventional hydraulic engine mount 10 is applied to a high-power diesel engine or the like, which produces vibration at a high-frequency range, it produces significant noises inside of the vehicle disadvantageously.